1. Field of the Invention
The present invention relates to an optical component composed by arraying a plurality of optical fibers.
2. Related Background Art
As an optical component for transmitting optical images, an optical component formed by arraying a plurality of optical fibers is widely known. The optical component has an incident plane and an exit plane exposing the core and clad of each optical fiber, and the optical image entering the incident plane is transmitted to the exit plane.
This optical component has numerous benefits including a high transmission efficiency and a smaller in size of optical system as compared with the lens, and is hence used in various fields such as fingerprint detecting system.
The optical component is usually manufactured by arraying and bundling a plurality of optical fibers in circular or square section, and forming integrally. Therefore, due to pressure at the time of integral forming, the section of the core of optical fibers for composing the optical component is transformed into polygonal shapes having mutually parallel diagonals such as square and hexagon, and the following problems occur.
That is, the light entering the incident plane with a specific incident angle is reflected repeatedly on the mutually parallel diagonals, and leaves the exit plane with a specific exit angle. As a result, a pattern having an intensity only in a specific exit angle is formed on the output image emitted from the exit plane, and this pattern becomes noise to lower the resolution of the optical component.
It is hence an object of the invention to solve such problems and prevent occurrence of pattern noise, and present an optical component of high resolution.
To solve the problems, the optical component of the invention is an optical component formed by arraying a plurality of optical fibers, in which each optical fiber comprises a first clad with a nearly circular section, a core formed around the first clad and having a refractive index larger than that of the first clad, and a second clad formed around the core and having a refractive index smaller than that of the core. In such configuration, the light entering the incident plane of the optical component is reflected repeatedly on the interface of the first clad and core and the interface of the core and second clad, and propagates through the core. Herein, since the section of the first clad is nearly circular, if the core is deformed to form mutually parallel opposite surfaces at the time of integral forming of the optical component, the situation of all light advancing like a band in the core is avoided, and it prevents formation of pattern having an intensity only in a specific exit angle. As a result, pattern noise is prevented, and an output image high in resolution can be obtained.
The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only and are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.